Combining Like Terms

Since being back in the classroom, I find myself doing activities with my lessons and thinking “I gotta blog about that.” These ideas may not be profound, but you never know if there’s some teacher out there in the universe that could use this cool thing.

One of my goals every year is for my students to make sense of math. And recently, one of our units (6th grade) was on equations and expressions. One of the topics was combining like terms.

I first pass out playing cards (poker cards) to each student. I made sure to use numbers 1 through 10. I also make sure I pass out a variety of clubs, diamonds, spades and hearts usually just the numbers 2-10.

Then I instruct the students to “combine like terms”. Now this is usually when they give me the most quizzical look. Then they try to ask a million questions, but I find myself just repeating myself with those 3 words. “Combine Like Terms!”

When it looks like the students have settled down and found their partner, I take a survey of what cards they put together. Here’s what they come up with.

We recorded the pairs of cards when given the instructions to “combine like terms”

Without even looking, I can predict this every year. And without any direction, I ask the students what their thinking was in pairing up. The answers I get are usually 1. The 2 cards are the same color. 2. the numbers are the same. 3. The numbers are even or 4. they cards are sequential.

After this initial pre-assessment, I show them examples of like terms and unlike terms. Usually I have at least one student who will connect the lesson with the card activity.

“Hey Mrs. A, what if we matched up the cards by the symbols?”

Bingo! Now we are onto something.

I proceeded to turning the playing cards into algebraic expressions. We used variables like D to represent for the diamond and H to represent the heart. Those can’t be combined because they don’t have the same variable. If you check back on the above picture…the only two cards that could be combined are the 7 of clubs and the 8 of clubs. Those students partnered up because the cards were “in order,” however they realized during our post-lesson discussion that they were the only pair that could be considered the same terms.

By using manipulatives and contextualizing an abstract algebra topic, it makes it a little easier for the students to grasp.